This invention relates to improvements in irrigation sprinklers. More specifically, this invention relates to a pop-up sprinkler having a spray head movable between retracted and elevated positions, and including means for preventing rotation of the spray head with respect to the housing when the spray head is in the elevated position.
Pop-up irrigation sprinklers in general are well known in the art. These sprinklers comprise a sprinkler housing including a coupling for attachment to a suitable line source of water under pressure. A pop-up stem is slidably received within the sprinkler housing, and carries a spray head through which water is sprayed for irrigation purposes. In operation, the pop-up stem is springably or gravitationally biased to a retracted position within the housing wherein the uppermost extent of the spray head is positioned substantially flush with the upper extent of the sprinkler housing and the ground. However, when water under pressure is supplied to the sprinkler housing, the pressure urges the stem to slide upwardly within the housing to carry the spray head to an elevated position above the housing. In this elevated position the water under pressure is emitted as a spray through the spray head for supplying irrigation water to a specified area.
In many instances, it is desirable to direct the irrigation water spray from the spray head generally in a selected direction. In other words, it is sometimes desirable to provide a so-called part circle spray head for use, for example, along the edge of a sidewalk or pavement so as to limit application of the water only to surrounding vegetation. In this regard, it is advantageous to provide a pop-up sprinkler having a spray head rotatable relative to the surrounding vegetation to permit adjustment of the spray head for accurate delivery of water in the desired direction.
In some applications, the sprinkler housing includes a vertically oriented coupling for connection to the water line source. With this type of coupling, it is possible to rotate the entire sprinkler housing and thereby correspondingly rotate the sprinkler spray head for obtaining the desired direction of irrigation spray. However, in such applications, rotation of the sprinkler housing with respect to the line source creates a relatively loose hydraulic connection which tends undesirably to leak, and which allows the housing to rotate on its own in response to vibrational forces during operation. Such relative rotation of the housing is undesirable in that the direction of irrigation spray is altered.
Some pop-up sprinklers include a housing with a horizontally oriented coupling for connection to a line source of water. These housings are not rotatable about a vertical axis for adjustment of the spray head direction. With sprinklers of this type, the pop-up stem is required to be rotated within the sprinkler housing, and this can be accomplished by providing a stem which freely rotates within the housing. However, with this type of construction, the prior art does not provide satisfactory means for locking the stem against rotation once the stem has been rotated to the selected direction, whereby these pop-up sprinkler units are highly susceptible to accidental or purposeful misalignment and misdirection of the irrigation spray resulting in improper irrigation and waste of water. Alternately, a rotationally locked stem can be provided, but this latter construction requires disassembly of the sprinkler unit in order to adjust the direction of the irrigation spray.
The present invention overcomes the problems and disadvantages of the prior art by providing an improved pop-up sprinkler including a pop-up stem with means for locking the stem against accidental or purposeful misdirection of the irrigation spray, and thereby maintain the stem in the selected position of adjustment.